Film gate and associated front end assembly of camera



o. s. HAMMER 3,102,448 FILM GATE AND ASSOCIATED FRONT END ASSEMBLY OFCAMERA Sept. 3, 1963 Filed Jan. 29, 1960 INVENTOR.

OLIVER S. HAMMER BY Mm ATTORNEY 1 3,102,448 FILM GATE AND ASSOCIATEDFRONT END ASSEMBLY OF CAMERA Oliver S. Hammer, New Albany, 1nd,;assignor to Unitcd Electronics Laboratories, Inc., Louisville, Ky.,' acon poration of Kentucky Filed Jan. 29, 1969, Ser. No. 5,514 4 Cs. (CI.88-17) This invention relates to improvements incarneiastor takingsequential photographs of the type shown in my copending U.,S.application, Ser; No. 835,246, filed August 21, 1959, now Patent No.3,011,416.

Myprior application points out that sequence cameras are useful lJLVallOllS applications including commercial, industrial and medical;that, in banks, stores and other establishments, the use of a sequencecamera may deter the commission of crimes such as robbery, shop-lifting,

3,1fl 2fl448 Patented Sept. 3, 1963 ice . 2 Certain of these objects areachieved by providing the camera with a film gate assembly which isseparate from [the camera frame and has a film seat adapted to engageand guide. the film vertically over a rectangular photovandalism, etc.,and assist in the identification of the per.

petrators thereof; in stores, factories and other places, it is usefulin recording the activities of sales persons and Workers, the flow ofmaterials and the operationof machines and equipment; and in medicalclinics and wards,

it is useful for recording behavior and other data useful makingclinical and psychiatric ward analyses.

For a sequence camera to be satisfactory for the above 2 uses, it shouldconsistently take good photographs; anything less than 100% efficien-tphotography cannot be tolerated for usually only a few of the manyphotographs taken are important and any poor photographs, even.

thoughthey be only'a small percentage of the total, may

be the very ones which are important.

greatly enlarged (blown up) to show small details clear- 1y. Hence, itis important that the photographs be accurately focused and'properlyframed on the film at all times, that thefil-rn not be scratched by thccamera mechanism and that any light leakage be avoided. It is alsoimportant that a sequence, camera be reasonablyeconomical to manufacturein order to be available an practical for the above use.

These .photo graphs should be of such excellence that they can be .Theprincipal object ofthis invention 'is substantially sequence camerastructure. I

-More specifically, animportant object of the present invention, inconnection with the taking of sequential to meet these-requirements andto provide an improved easily and quickly installed, loaded andunloaded, which will consistently center the operative frames of eachsuccessivefilm properly and maintain them in exact focus without.scratching or otherwise damaging the film or subjecting it toundesirable light leaks and which will operate over a long period oftime in a trouble-freemannerxconsistently taking good photographswithout requiring attention.

- Other objects of this invention are: to provide a semanufactured ofmoldedor cast parts; to simplify and reduce the number of machining'operations ordinarily required in manufacturing a camera orthis'type;and to i provide a sequence ,camerawhich can be accurately ascameraframe. Such a film gate can be and preferably is made of a molded orcast material such as one of the modern plastics which does not scratchthe film as it travels through the film gate. In addition to theseadvantages, the presser plate of the disclosed film gate is .tiltableabout a vertical axis on the film seat to open the gate, for allowingthe film tobe threaded through the gate, and this is simply andeffectively accomplished by pinching the accessible vertical side marginof the if presser plate forwardly against the film seat.

Other objects are accomplished by substantially reducing the number andthe complexity of the machining operatio-ns necessary in manufacturingthe camera These have been reduced to a few relatively simpleoperationswherein fiat'surfaces are leveled and reduced to apredetermined thickness,

The accompanying drawing illustrates the invention wherein: g 7

FIG. 1 is a fragmentary section taken along a vertical plane extendingcentrally through the front of the camera and'its lens; FIG. 2 is anenlarged perspective view of the film gate shown in FIG. 1;

FIG. 3. is similar to'FlG. 2 with the film gate being opened foraccommodating the threading of film through it; FIG. 4 is an explodedperspective view of the film gate; FIG, 5 is a section taken on line5--5 of FIG: 2; and FIG. 61 is a fragmentary view of the film gateshowing the framing aperture. i

The camera structure shown in FIG. 1 of the drawing generally includes:the fnont wall 1 of a camera case conaperture 2; a'shutter 6 disposedbetween said front Wall and base apertures for controlling light passingthrough said apertures; film handling means mounted on" said frame andincludinga film gate 7 mounted on therear side of said base over saidbase aperture, an idler pulley 8 and'a film pull-down sprocket 9 forpulling film through said film gate 7; and alens mount 10 mounted on theoutquence camera construction which can be economically side of saidfront wall 1 over said case aperture. The above. structure is shown andspecifically described, along with other camera structure, in mypreviously mentioned.

co-pending application Serial No. 835,246.

Improvements shown in the drawing include: a novel film gate; and anovel assembly of the film gate, frame base, case front wall, and lensmount.

. FILM GATE The novel film gate 7 'showninthe drawing includes: a filmseat for receiving and guiding film over the photographing apertures; :apresser plate for pressing the film against the film seat; meansconnecting said film seat and presser plate together; meansfor tiltingsaid presserplate 7 on said film seat for opening said film gate; andmeans approximating'the film thickness.

9 o- 1 a a for biasing said film seat and presser plate together on a Isprings 26. The springs 33 cooperate with the springs 26 toprovide aturning force (turning couple) which swings and biases the presser plateshoe 21 into the channel space V 15. The importance of both pairs ofsprings 26 and 33 is seen when one recognizes the need for keeping thepresser plate shoe 21 pressed against the film across substantially allof its widthwith a substantially uniform pressure. .This result isreadily achieved with my arrangement of two pairs of springs, whereas itwould not nor- The film seat is mounted by anchoring this thicker leg orportion 17 to the base 4 of the camera frame 3.

A rectangular photograph framing aperture 18 is con 1 trallyprovid ed inthe bight 14. This aperture 18 is aligned with thecase front wall andbase apertures 2 and in the mounted position of the film gate. Theperipheral edges forming the framing aperture 18 may be beveled on thefront side as shown in FIGS. 1 and 6 to reduce the thickness of theedges of the framing aperture. Preferably,

' the film seat is composed of a black non-reflecting molded plastic.

. Presser Plate t Thepresser plate 20- rests on the rear of the filmseat '14 and has a vertically elongate shoe 21 fitting in and,

substantially filling the channel space 15. The front face of the shoe21 isadapted to engage the rear face of the film and press it againstthe film seat bight 14. Hence,- the shoe 21 is smooth and curvedrearwardly at both its 4 upper and lower ends to avoid scratching orotherwise marring the film. This construction enables the use of anidler sprocket, at the upper end of the gate, to be elimi nated. {Thepresser plate 20 is mounted by the tongue or portion 22 which extendsfrom one side of the shoe 21.

The presser plate 20 is normally composed of the same material as thefilm seat 14. i

Connection M eans The film seat 14 and presser plate 20 are connectedtogether by a pair of bolts-24 extending rearwardly through the thickleg of portion 17 of the film seat and the tongue portion 22of thepresser plate. Nuts 25 are threaded on the rear ends of the bolts 24 andrespective compression springs-26 are interposed on the bolts 24 betweenthe presser plate 20 and the nuts 25 for biasing the presser plateforwardly against the film seat 14. I

Tilting Means I plate 20 on the film seat 14, the vertically extendingrear edge portion, of the thick leg 17 of" To tilt the presser the filmseat 14, is'chamfered to provide a bevel 28. The

bevel 28 meets the flat rear face 29 of the film seat portion along avertical line or axis designated 30 which serves as a fulcrum aboutwhich the presser plate 20' tilts 'in openingand closinglthe film gate.'enables the presser plate 20 to betilted to an open posi- Thisconstruction tion about the fulcrum30 simply by pinching the portions 17and .22 together along their outer vertical edges, as shown in FIG. 3.In FIG. 5, plate 22 and fulcrum line 30 are "shown spaced from eachother} by a distancev Gate Biasing Means As the bolts 24 are disposedvin the portion 17 between the fulcrum 30 and the channel space '15, thesprings 26 on these bolts act to bias the pressure plate 20 about thefulcrum 3'0 to close the film gate; The tension on the. springs 26 isreadily adjusted by turning the nuts 25.

In addition, another pair of compression springs 33 are disposed betweenthe portions 17 and 22 on the other side of the fulcrum 30 from thebolts 24 and channel space 15. These latter springs '33: seat in'therecesses '34 formed in the bevel '28 of the film seat and are weakerthan the mally be attained by using only one pair of springs. The

tension on the springs 26 need only be adjusted, by turning the'nuts 25,until reaching the point where the forces created by thesprings 26 and33 result in auniform pressure across the width of the shoe. '7

, ASSEMBLY This assembly includes: means mounting the film gate 1 p onthe trame base; means mounting the frame base on the case front wall;and means mounting the lens mount on the case. I a

Film Gate M b unting eans v The gate '7 is mounted onthe frame base 4 bythe same bolts 24 that hold the film seat 14 and pressure plate 20together. The front face oflthe film 'se-at. 14 rests on the rear faceof the frame 1 ass 4 with the base aperture 5 aligned with thephotograph framing aperture 18 in the film seat 14, the bolts 24extendrearwardly through v appropriate holes in the base 4. As seen inFIG. 4, nuts 36 are threaded over the rear ends of the bolts 24 andscrewed down tightly against the rear side of thefilrn seat 14 to clampthe seat against the base. Appropriate recesses 37 are formed in therear face 29 of the fil'm'seat 14' to receive the nuts 36 andoitsettheminwardly from the plane oftlie rear face 29. The recesses'37 also lockthe nuts 36 against turning; Of course, the film seat 14 (is mounted onthe frame base 4 before the pressure plate 20 is mounted on the filmseat 14. 4

Frame Base Mounting Means" Both the front and rear faces ofthe framebase 4 are machined to level them and give the base a predeterminedthickness. The inner face of the case front wall 1 is also machined togive the front wall a predetermined thickness. These are the onlymachining operations performed. g in preparing the film gate, framebase, case and lens mount for assembly together. The frame base 4issimply attached to the case-front wall 1 bythe two screws 39 shown FIG.1; By machining both the front wall 1 of the case and the frame base 4,to a predetermined thickness, these parts fit tightly together and havea combined thickness of predetermined order.

Lens Mounting M eons An escutoheon plate '41 of a predeterminedthickness and having an appropriate internally threadedhole 42 thereinis attached on the outside of the caseJfront walll' with its hole 42aligned with the case aperture 2.

attachment is accomplished simply by several screws 43.

extending through the escutcheon plate'and threaded into the frontwall 1. Since the escutcheon plate 41, the case front wall 1 and thettrani e base 4 are all of a predetermined thickness, once the lensmount 10 is attaohedto the escntoheon plate 41 by screwing'the mountinto th internallythreaded hole 42 until the shoulder of the mount fitstightly against the escutche'on plate, the lens mount 10will be at aprecise predetermined distance rmmne, r film supported in the'film gate7. The plate-engaging snrri face of the shoulder of the mount is spaceda fixed prea determined distance from-the film in all standard lensmounts, regardless of focal length; hence it provides a fixed referencepoint which insures proper focus.

SUMMARY It "will be understood, from the foregoing: that the front wallof case land the base 4 of trame 3 are ma- 'chined on either or both thefront and rear sides, as may be -necessary, to provide them with anaccurately predetermined thickness and flatness; and that the film seat14,

ro-ckablyltoward an operative position in which they are spaced apartinthe tilting section and-brought together in is molded or cast to anaccurate thickness between its 1 front and rear sides and a desireddegree of fiatnessi'on both sides. The plate 41 may be a metalplate-manuin .a fixed relationship to each other; hence, itis conre- Ispondingly easyto center the framing aperture 18 accurately respect tothe axis of the lens mount ll).

Furthermore, it is easy to center each successive frame of. the filmboth transversely and longitudinally with respect to the framingaperture 18. Transverse centering is accomplished by means of the legs16, 17 which engage the side edges of the film to guide that filmaccurately through the seat 14. Longitudinal centering is secured byconventionally adjusting the angular position of the take-up sprocket 9relative to the film drive mechanism. An advantage of myforegoingarrangement arises from the fact that, withrespect to all lighttransmitting apertures on the rear side of the bore of the lens mount10,

the framing aperture 18, which is smaller than the bore of the lensmount 10, is the only aperture, which needs to be of an accuratelypredetermined size, so long as the other intervening apertures arelarger. This makes it possible to eliminate any machining'of theselarger apertures, including those whichheretotore have had to I bemachined accurately at substantial expense.

The sensitized space of each frame of a 16 mm. film approximates by %0.The standard picture taken' in that" space approximates' by I have foundit possible to enlargevmy framing aperture 18 to take a picture whichapproximates 4 m y instead of This has the advantage of enabling a givencamera, having a lens of given focal length, to photograph acorrespondingly larger area without reduch g the scale of theobjectsphotographed. It will be understood, of course, thatwhile alarger area may be photographed on the same camera and the same filmwith a wider angled lens, the" scale of the objects photographed iscorrespondingly reduced in such case.

My novel film gate can be considered as containing the followingstructure: a stationary front plate-like member and a relatively movablerear presser plate normally arranged in stationary face-to-facerelationship to provide, in cooperation with eachother, a'fulcrumsection interthe film section.

My lens-gate structure inherently provides a fixed predetermineddistance between the film and the fixed reference point of r a standardlens mount and thus insures an accurate focus with any of a variety ofstandard lens mounts. This lens-gate structure may be viewed ascomprising: a plate-like. assembly; an outside lens mount 10; and aninside film gate-7.. Y

The plate-like assembly includes a camera case member 1 having a frontwall interposed between a front escutcheon plate member 41 and a rearcamera-(frame member 4. Each member of this plate-likeassembly contains.a light-transmitting aperture, such as aperture 2 in the case member 1.-Each presents, on its front and rear faces, flat-faced frontand rearseating surfaces separated.

by :a predetermined thickness. These members are collectively arrangedin rear-face to front-face relationship proceeding from the frontrearwardly. They are rigidly secured together with all of their lightapertures aligned and with the seating surfaces on their adjacentfacesin flush face-to-face engagement so that front and rear faces of theassembly, as a Whole, are separated by a predetermined thickness.

The outside lens mount 10 is positioned onthe front side of theplate-like assembly and secured to the front esoutcheon plate 41 toproject forwardly therefrom in alignment with all of said lightapertures. It has :a rear seating surface which is in face-to faceengagement with the front seating surface of the front plate 41 andwhich provides a fixed reference point for proper lens-focusing purposessince it is spaced a fixed distance from the film.

The inside film gate 7 is positioned on the rear side of said plate-likeassembly and secured to the rear frame 4. it has a front face aperture18 alignedwithsaid other apertures. It provides a passageway for thepassage of a film across its aperture 18 for film-frame exposingpurposes. llt also has a front seating surface in flush face-to \faceengagement with the rear seating surface of said rear frame 4 and isoperative to hold a film frame during exposure at a predetermineddistance from its front seat ing surface and thereby hold said filmframe at a fixed 7 distance from said fixed reference point on the lensmount.

Having described my invention, I claim: 1. A lens-gate structure for asequence camera of th movable film type, comprising:

posed between film and tilting sections, the adjacent faces of: thefront member and of the rear plate providing surfaces in :theflrlcrumsection which extend along a comnion longitudinally-extendingaxis thatis spaced laterally from both longitudinal edges of the gate, surfacesin the film section which cooperate to provide between the fulcrumsection and one longitudinal edge of thegate an crum section securingthe presser plate yieldably to the front member for relative rocking movement about said I common longitudinal axis and for relative back andforth translation movement, said means including a stemextendjingtransversely through the fulcrum section and projecting fromone of the front and rear faces of the gate and first yieldable meansassociated with said projecting stem to urge the-front memberand rearplate of the gateylieldably together;and second yield'able meansdisposed along the tilting. space to urge the front member and rearplate A. a plate-like assembly including a camera case memher having afront wall interposed between a front 'escutc'heon plate member and arear camera-frame member, i

' (1) each member of said plate-like assembly containing a front-to-rearlight-transmitting aperture and being of substantially flat solidplatelike form presenting, on itsfront and rear faces,

" flat-faced front and rear seating surfaces separated by apredetermined thickness,

(2) said members being arranged in rear-face to front-face relationshipproceeding from the front rearwardly, p 1

'(3) at least one of the adjacent faces of said camera case andcamera-frame members being 'recessed so that both members cooperate toform a shutter chamber;

B. means securing the members of said plate-like assembly rigidlytogether (1) with all of said light apertures aligned, and

(2) with the seating surfaces on-their adjacent tures,

J (1) said lens mount having a rear seating sunfiace,

' (a) which is in face-to-face engagement with the front seating surfaceof said front es-- "cutcheon plate and (b) wlhichprovides a fixedreference point for proper lens-focusing purposes; and Dian-inside filrngate positioned'on the rear side of section; 1

B. said front and rear members of said film gate unit are resilientlyconnected together-along said fulcrum section by said connecting meansfor relative rockting movement about said common longitudinal axis.

and for relative back and forth translation movement,

said plate-llike assembly and'rnounted 'onrsaidrear I v 1 (1) saidconnecting means including V (a) a stem extending transversely throughthe fulcrum section and projecting from one of the front and rear facesof the gate'and (b) first yieldable means associated withsaid projectingstem to urge the front member and rear plate of the gate yieldably.together; C. said film gate is provided ,Wl th second yieldable meansdisposed along the'tiltin'g space to urge the front member and rearplate rockahly toward an operative position in which they are spacedapart in the tilting section and brought together'in the film section;and t 1 Dpsaid first and second yield-able means cooperating,

camera-frame member, a Y

(1) said gate being composed of front and rear members with connectingmeans extending thnough said front and rear members,

(a) said connecting means comprising means for firmly securing 1 said 6front member against said rear camera-frame member and resilientmeansipressing said rear member 'of the gateyieldably against said frontmember thereof, ,4 (2) said 'gate having lateraliy-spaced. l0ngially-extending edges and providing therebetween alongitudinally-extending open-ended slot-like film passageway for thepassage of a film across its aperture for film-frame exposing purposes,i (3) the front member of said gate having a frontto-rearlight-transmitting aperture aligned with said other apertures and afront seating surface in flush face-to-face engagement with the rearseating surface ofsaid rear camera firame and -being+operative, incombination with the rear member of said gate to hold a film frame forexposure purposes at a predetermined distance from its front seatingsurface and thereby'hold said 'filni'lfr'ame at afixed distance fromsaid fixed reference point. 2. The lens-gate structure of claim 1wherein: A. said front and rear members of said film gate cornprise astationary front plate-like member and a relatively movable rear presserplate normally arranged able rear pressure plate in a direction pressingits film section yieldably forward and thereby cause both the frontmember and theirear plate to press faces of an interposedifilm.

film gate:

nel on the rear face of said front gate member along its filmpassageway, f the side walls of said channel and I curved rearwardlyfrom its front'face at its opposite ends adjacent the ends of saidchannel.

in said operative position, to rock said relatively movuniformly intoslidable engagement with opposite 3. The lens-gate structure of claim 2wherein, said A. a film seat is formed by a rearwardly opening chanyengaging and guiding the film along said passageway; I I j B. saidpresser plate has a forwardly projectingfl-at faced shoe 1 seating insaid channel, said shoe-being cooperation with each other, a fulcrumsection interposed betwcenvfilm and tilting sections,

(1) the adjacent faces of the stationary front v in stationaryface-to-face relationship to provide, in

member and of the movablerear plate profilm gate:

4. The lens-gate structure of claim 2 wherein, in said A; said stemextends forwardly through and protrudes beyond the front face of saidfront plate-like member for securing said film gate to said rear cameraframe t 7 member.

(a) opposed surfaces in the fulcrum section 'which extend along a commonlongitudinally-extending axis that is spaced later- References Qitedinthe file of this patent UNITED STATES PATENTS Wittle j Mar. 6, 1928'ally from both longitudinal edges of the 7 "gate, 1 767 847 Howell.June241930 (b) opposed surfaces in the film section 1933066 Merl 7 Oct311933 hich cooperate to provide said longitue "7 v v I p 1,979,984Moomaw Nov. 6,1934 d1nally-extend1ngfilm' passageway between .5 2 003691 Lu dber Jung 4 1935 the fulcrum section and one lon itudinal n *7' vj t a 2,249,228 Rogers July 15, 1941 edge of the gate, and

2,733,062 De Valleetal. -I an.-31,1956

(c) opposed surfaces in' the tilting section

1. A LENS-GATE STRUCTURE FOR A SEQUENCE CAMERA OF THE MOVABLE FILM TYPE,COMPRISING: A. A PLATE-LIKE ASSEMBLY INCLUDING A CAMERA CASE MEMBERHAVING A FRONT WALL INTERPOSED BETWEEN A FRONT ESCUTCHEON PLATE MEMBERAND A REAR CAMERA-FRAME MEMBER, (1) EACH MEMBER OF SAID PLATE-LIKEASSEMBLY CONTAINING A FRONT-TO-REAR LIGHT-TRANSMITTING APERTURE ANDBEING OF SUBSTANTIALLY FLAT SOLID PLATELIKE FORM PRESENTING, ON ITSFRONT AND REAR FACES, FLAT-FACED FRONT AND REAR SEATING SURFACESSEPARATED BY A PREDETERMINED THICKNESS, (2) SAID MEMBERS BEING ARRANGEDIN REAR-FACE TO FRONT-FACE RELATIONSHIP PROCEEDING FROM THE FRONTREARWARDLY, (3) AT LEAST ONE OF THE ADJACENT FACES OF SAID CAMERA CASEAND CAMERA-FRAME MEMBERS BEING RECESSED SO THAT BOTH MEMBERS COOPERATETO FORM A SHUTTER CHAMBER; B. MEANS SECURING THE MEMBERS OF SAIDPLATE-LIKE ASSEMBLY RIGIDLY TOGETHER (1) WITH ALL OF SAID LIGHTAPERTURES ALIGNED, AND (2) WITH THE SEATING SURFACES ON THEIR ADJACENTFACES IN FLUSH FACE-TO-FACE ENGAGEMENT SO THAT THE FRONT AND REAR FACESOF THE PLATE-LIKE ASSEMBLY AS A WHOLE ARE SEPARATED BY A PREDETERMINEDTHICKNESS;